Intermediate Temperature Parameter for PG Asphalt Binders. Asphalt Binder Expert Task Group Meeting 16 September 2014 Baton Rouge, LA

Transcription

1 Intermediate Temperature Parameter for PG Asphalt Binders Asphalt Binder Expert Task Group Meeting 16 September 2014 Baton Rouge, LA

2 Asphalt Binder ETG: Intermediate Temperature Parameter Task Force Task Force Mike Anderson Dave Anderson Hussain Bahia Pouya Teymourpour Gaylon Baumgardner Gayle King Bob McGennis Jean-Pascal Planche Gerald Reinke Geoff Rowe Hassan Tabatabaee

3 Intermediate Temperature Parameter Task Force Purpose To evaluate the existing intermediate temperature parameter and criterion in AASHTO M320 and MP332 and, if necessary, revise and/or develop one or more parameters that: do not require significantly more testing than the current intermediate temperature parameter (G*sin δ) determined using AASHTO T315; have reproducibility at least comparable to, but preferably better than the d2s% values for the current intermediate temperature parameter; and are related to the rheological and failure properties of the asphalt binder at intermediate temperature.

4 Intermediate Temperature Parameter Evaluation Materials It has been suggested that the asphalt binders being produced today may be different enough from the SHRP binders that the G*sin δ parameter and/or the criterion may not be applicable.

5 Intermediate Temperature Parameter Evaluation Old Conventional SHRP MRL asphalt binders Used in developing the current PAV DSR parameter New Conventional Current production Represent cross-section of asphalt binders in US AI to acquire approximately 50 gallons of each for current and future testing. AI to distribute samples as needed to the testing labs New Unconventional Asphalt binders formulated by Bob McGennis (HollyFrontier) to represent binders that are expected to have some unusual intermediate temperature responses compared to New Conventional asphalt binders

6 Old Conventional Asphalt Binders SHRP MRL Binders Used in developing the current PAV DSR parameter Evaluate existing data New testing conducted Linear Amplitude Sweep Conducted on RTFO- and PAV-aged binder at 15, 20, and 25 C Additional temperatures for PAV-aged binders corresponding to T int (according to M320 grade)

7 LAS Data for AAA: Comparison of Temperature Effect at Varying Aging 1.0E E+07 AAA Cycles to Failure, N f 1.0E E E+04 RTFO-15 RTFO-20 RTFO E Shear Strain, % 1.0E E+07 AAA Cycles to Failure, N f 1.0E E E E+03 PAV-15 PAV-20 PAV E Shear Strain, %

8 LAS Data for AAA: Comparison of Aging Effect at Varying Temperature 1.0E E+06 AAA 1.0E E+07 AAA Cycles to Failure, N f 1.0E E E+03 RTFO-15 PAV-15 Cycles to Failure, N f 1.0E E E+04 RTFO-20 PAV E Shear Strain, % 1.0E Shear Strain, % 1.0E+08 AAA Cycles to Failure, N f 1.0E E E E+04 RTFO-25 PAV E Shear Strain, %

9 LAS Data for AAA: Comparison of Temperature and Aging Effects at Constant Strain 3% Strain, Cycles 120, ,000 80,000 60,000 40,000 20,000 AAA y = 6.433x R² = y = x R² = AAA-R AAA-P Power (AAA-R) Power (AAA-P) Temperature, C

10 Old Conventional Asphalt Binders SHRP MRL Binders New testing conducted Temperature-Frequency Sweep Conducted on Original, RTFO-aged, and PAV-aged binders Temperature sweep from 5-55 C Frequency sweep from 0.1 to 100 rad/s (10 pts/decade) BBR Testing Conducted on Original, RTFO-aged, and PAV-aged binders Used with temperature-frequency sweep data to complete mastercurve Mastercurve analysis Geoff Rowe

11 Mastercurve: AAG-Original

12 Black Space: AAG-Original

13 Mastercurve: AAM-Original

14 Black Space: AAM-Original

15 Old Conventional Asphalt Binders SHRP MRL Binders New testing conducted DSC Differential Scanning Calorimeter Used to determine glass transition and crystallization properties Conducted by Western Research Institute Testing complete on AAD, AAG, AAK, and AAM for all three aged conditions (Original, RTFO, and PAV) SAR-AD Automated saturates, aromatics, resins, and Asphaltene Determinator (AD) Conducted by Western Research Institute Testing complete on AAD, AAG, AAK, and AAM for all three aged conditions (Original, RTFO, and PAV)

16 DSC Results

17 Old Conventional Asphalt Binders SHRP MRL Binders New testing conducted Torsion Bar Conducted by MTE Services Testing on AAD, AAG, AAK, and AAM for all three aged conditions (Original, RTFO, and PAV) 4-mm Parallel Plate DSR Conducted by MTE Services Testing complete on AAD, AAG, AAK, and AAM for all three aged conditions (Original, RTFO, and PAV) Vialit Coordinated by Geoff Rowe Analysis forthcoming

18 New Conventional Asphalt Binders New Conventional Current production Represent cross-section of asphalt binders in US Approximately 8-10 binders Eight sources (50 gallons each) now at AI M320 testing followed by additional testing TBD

19 New Conventional Binders: M320 NC-A NC-B NC-C NC-D NC-E NC-F NC-G NC-H Tc,O-DSR Tc,R-DSR Tc,P-DSR Tc,P-G* ΔTc,Int δ at Tc,P- DSR Tc,S Tc,m ΔTc,Low Grade

20 New Conventional Binders

21 New Conventional Binders

22 New Conventional Binders LAS Testing Two temperatures Intermediate grade temperature (T int ), T int -3 C LAS Temperature, C Tc,P-DSR, C NC-A PG NC-B PG NC-C PG NC-D PG NC-E PG NC-F PG NC-G PG NC-H PG * 34.7

23 New Conventional Binders: LAS

24 New Conventional Binders: LAS Slope (B) as f(t)

25 New Conventional Binders: LAS Slope (B) as f(δt c,low )

26 New Conventional Binders: LAS Slope (B) as c,p-dsr )

27 New Conventional Binders: LAS N f at 3% Strain and Grade T int

28 New Conventional Binders: LAS N f at 3% Strain and Grade T int Tc = 18.7 Tc = 15.6 Tc = 17.1 PG 58-28

29 New Unconventional Binder Testing Matrix Soft Blend Component Hard Blend Component PDA Asphalt SDA Asphalt ROSE Pitch from WTS ROSE Pitch from WCS Low Vis Aromatic Oil x x x x High Vis Aromatic Oil x x x x Soft PDA Asphalt x x x x REOB #1 REOB #2 x x Waste Motor Oil x x Low Vis VTB (low temp spread) x x x x x Other materials: Non-blended material PG (oxidized binder) PG binder containing Fisher-Tropsch wax PG binder containing oxidized polyethylene wax

30 New Unconventional Asphalt Binders New Unconventional Binder Testing Targeting C and testing as PG MSCR Thanks to Bob McGennis and Thomas Ludlum, both HollyFrontier Purpose Evaluate New Unconventional binders and determine which to include in complete testing program

31 New Unconventional Asphalt Binders

32 New Unconventional Asphalt Binders

33 Next Steps Conference Call September 2014 General agreement that we still have some effort to go before we solve the issue Aging still a consideration May need to get more aging than is currently provided by PAV practice WRI USAT one possible option So what can we do within the existing specification? Capturing effects of excessive age-related cracking? R-value Minimum phase angle at intermediate temperature grade (or more appropriately at G*=5000 kpa) ΔTc

34 Old Conventional Asphalt Binders: R-Value as a Function of Phase Angle R-Value Phase Angle at G*=5000 kpa

35 Old Conventional Asphalt Binders: R-Value as a Function of ΔTc R-Value ΔTc

36 Next Steps Continue Evaluation of Old Conventional Asphalt Binders 4-mm PP DSR, DSC, SAR-AD, Vialit, LAS Other Continue Evaluation of New Conventional Asphalt Binders Selected tests Select New Unconventional Asphalt Binders for Evaluation

37 Thanks!